/* Determine whether arguments can be added without overflow */
/* WARNING: This code is buggy. */
int tadd_ok(int x, int y) {
    if(x>0&&y>0){
        return x+y>x;
    }else if(x<0&&y<0){
        return x+y<x;
    }else return 1;
    // return (sum - x == y) && (sum - y == x); always true
}